Use of a cable network to deliver programming content, e.g., TV programs, is ubiquitous. The cable network terminates on set-top boxes at the user premises. It is well known that the cable network also provides program guide data to the set-top boxes from time to time. The program guide data typically contains broadcast time and channel information concerning each program to be broadcast within a predetermined period. The program guide data may be used to populate an interactive program guide (IPG) facilitating a user's access to desired programs. After receiving the program guide data from the cable network, the set-top box stores it in a memory therein, which is updated to provide the latest IPG.
Nowadays, the number of program channels and the amount of programming content delivered over a cable network are ever increasing. At the same time, the number and types of cable services, e.g., video-on-demand (VOD) services, introduced to enhance a user's program enjoyment are ever growing. As a consequence, the amount of program guide data concerning broadcast programs, on-demand programs, etc. which needs to be transmitted to set-top boxes is also ever increasing. In prior art, the limited bandwidth of the cable network for transmitting program guide data is no longer sufficient for effectively transmitting the increasing guide data. Similarly, in prior art, the limited memory capacity of a set-top box is no longer sufficient for accommodating the increasing guide data.